/// <summary>
/// Constructs a join propagator.
/// </summary>
/// <param name="left">Result of propagating changes in the left input to the join</param>
/// <param name="right">Result of propagating changes in the right input to the join</param>
/// <param name="node">Join operator in update mapping view over which to propagate changes</param>
/// <param name="parent">Handler of propagation for the entire update mapping view</param>
internal JoinPropagator(ChangeNode left, ChangeNode right, DbJoinExpression node, Propagator parent)
{
EntityUtil.CheckArgumentNull(left, "left");
EntityUtil.CheckArgumentNull(right, "right");
EntityUtil.CheckArgumentNull(node, "node");
EntityUtil.CheckArgumentNull(parent, "parent");
m_left = left;
m_right = right;
m_joinExpression = node;
m_parent = parent;
Debug.Assert(DbExpressionKind.LeftOuterJoin == node.ExpressionKind || DbExpressionKind.InnerJoin == node.ExpressionKind, "(Update/JoinPropagagtor/JoinEvaluator) " +
"caller must ensure only left outer and inner joins are requested");
// Retrieve propagation rules for the join type of the expression.
if (DbExpressionKind.InnerJoin == m_joinExpression.ExpressionKind)
{
m_insertRules = s_innerJoinInsertRules;
m_deleteRules = s_innerJoinDeleteRules;
}
else
{
m_insertRules = s_leftOuterJoinInsertRules;
m_deleteRules = s_leftOuterJoinDeleteRules;
}
// Figure out key selectors involved in the equi-join (if it isn't an equi-join, we don't support it)
JoinConditionVisitor.GetKeySelectors(node.JoinCondition, out m_leftKeySelectors, out m_rightKeySelectors);
// Find the key selector expressions in the left and right placeholders
m_leftPlaceholderKey = ExtractKey(m_left.Placeholder, m_leftKeySelectors, m_parent);
m_rightPlaceholderKey = ExtractKey(m_right.Placeholder, m_rightKeySelectors, m_parent);
}
/// <summary>
/// Constructs a join propagator.
/// </summary>
/// <param name="left">Result of propagating changes in the left input to the join</param>
/// <param name="right">Result of propagating changes in the right input to the join</param>
/// <param name="node">Join operator in update mapping view over which to propagate changes</param>
/// <param name="parent">Handler of propagation for the entire update mapping view</param>
internal JoinPropagator(ChangeNode left, ChangeNode right, DbJoinExpression node, Propagator parent)
{
EntityUtil.CheckArgumentNull(left, "left");
EntityUtil.CheckArgumentNull(right, "right");
EntityUtil.CheckArgumentNull(node, "node");
EntityUtil.CheckArgumentNull(parent, "parent");
m_left = left;
m_right = right;
m_joinExpression = node;
m_parent = parent;
Debug.Assert(DbExpressionKind.LeftOuterJoin == node.ExpressionKind || DbExpressionKind.InnerJoin == node.ExpressionKind, "(Update/JoinPropagagtor/JoinEvaluator) " +
"caller must ensure only left outer and inner joins are requested");
// Retrieve propagation rules for the join type of the expression.
if (DbExpressionKind.InnerJoin == m_joinExpression.ExpressionKind)
{
m_insertRules = s_innerJoinInsertRules;
m_deleteRules = s_innerJoinDeleteRules;
}
else
{
m_insertRules = s_leftOuterJoinInsertRules;
m_deleteRules = s_leftOuterJoinDeleteRules;
}
// Figure out key selectors involved in the equi-join (if it isn't an equi-join, we don't support it)
JoinConditionVisitor.GetKeySelectors(node.JoinCondition, out m_leftKeySelectors, out m_rightKeySelectors);
// Find the key selector expressions in the left and right placeholders
m_leftPlaceholderKey = ExtractKey(m_left.Placeholder, m_leftKeySelectors, m_parent);
m_rightPlaceholderKey = ExtractKey(m_right.Placeholder, m_rightKeySelectors, m_parent);
}
/// <summary>
/// Performs join propagation.
/// </summary>
/// <returns>Changes propagated to the current join node in the update mapping view.</returns>
internal ChangeNode Propagate()
{
// Construct an empty change node for the result
ChangeNode result = Propagator.BuildChangeNode(m_joinExpression);
// Gather all keys involved in the join
JoinDictionary leftDeletes = ProcessKeys(m_left.Deleted, m_leftKeySelectors);
JoinDictionary leftInserts = ProcessKeys(m_left.Inserted, m_leftKeySelectors);
JoinDictionary rightDeletes = ProcessKeys(m_right.Deleted, m_rightKeySelectors);
JoinDictionary rightInserts = ProcessKeys(m_right.Inserted, m_rightKeySelectors);
var allKeys = leftDeletes.Keys
.Concat(leftInserts.Keys)
.Concat(rightDeletes.Keys)
.Concat(rightInserts.Keys)
.Distinct(m_parent.UpdateTranslator.KeyComparer);
// Perform propagation one key at a time
foreach (CompositeKey key in allKeys)
{
Propagate(key, result, leftDeletes, leftInserts, rightDeletes, rightInserts);
}
// Construct a new placeholder (see ChangeNode.Placeholder) for the join result node.
result.Placeholder = CreateResultTuple(Tuple.Create((CompositeKey)null, m_left.Placeholder), Tuple.Create((CompositeKey)null, m_right.Placeholder), result);
return(result);
}
/// <summary>
/// Produce a tuple containing joined rows.
/// </summary>
/// <param name="left">Left row.</param>
/// <param name="right">Right row.</param>
/// <param name="leftKey">Key used to join left element.</param>
/// <param name="rightKey">Key used to join right element.</param>
/// <param name="result">Result change node; used for type information.</param>
/// <returns>Result of joining the input rows.</returns>
private PropagatorResult CreateResultTuple(Tuple <CompositeKey, PropagatorResult> left, Tuple <CompositeKey, PropagatorResult> right, ChangeNode result)
{
// using ref compare to avoid triggering value based
CompositeKey leftKey = left.Item1;
CompositeKey rightKey = right.Item1;
Dictionary <PropagatorResult, PropagatorResult> map = null;
if (!object.ReferenceEquals(null, leftKey) &&
!object.ReferenceEquals(null, rightKey) &&
!object.ReferenceEquals(leftKey, rightKey))
{
// Merge key values from the left and the right (since they're equal, there's a possibility we'll
// project values only from the left or the right hand side and lose important context.)
CompositeKey mergedKey = leftKey.Merge(m_parent.m_updateTranslator.KeyManager, rightKey);
// create a dictionary so that we can replace key values with merged key values (carrying context
// from both sides)
map = new Dictionary <PropagatorResult, PropagatorResult>();
for (int i = 0; i < leftKey.KeyComponents.Length; i++)
{
map[leftKey.KeyComponents[i]] = mergedKey.KeyComponents[i];
map[rightKey.KeyComponents[i]] = mergedKey.KeyComponents[i];
}
}
PropagatorResult[] joinRecordValues = new PropagatorResult[2];
joinRecordValues[0] = left.Item2;
joinRecordValues[1] = right.Item2;
PropagatorResult join = PropagatorResult.CreateStructuralValue(joinRecordValues, (StructuralType)result.ElementType.EdmType, false);
// replace with merged key values as appropriate
if (null != map)
{
PropagatorResult replacement;
join = join.Replace(original => map.TryGetValue(original, out replacement) ? replacement : original);
}
return(join);
}
/// <summary>
/// Propagate all changes associated with a particular join key.
/// </summary>
/// <param name="key">Key.</param>
/// <param name="result">Resulting changes are added to this result.</param>
private void Propagate(CompositeKey key, ChangeNode result, JoinDictionary leftDeletes, JoinDictionary leftInserts,
JoinDictionary rightDeletes, JoinDictionary rightInserts)
{
// Retrieve changes associates with this join key
Tuple <CompositeKey, PropagatorResult> leftInsert = null;
Tuple <CompositeKey, PropagatorResult> leftDelete = null;
Tuple <CompositeKey, PropagatorResult> rightInsert = null;
Tuple <CompositeKey, PropagatorResult> rightDelete = null;
Ops input = Ops.Nothing;
if (leftInserts.TryGetValue(key, out leftInsert))
{
input |= Ops.LeftInsert;
}
if (leftDeletes.TryGetValue(key, out leftDelete))
{
input |= Ops.LeftDelete;
}
if (rightInserts.TryGetValue(key, out rightInsert))
{
input |= Ops.RightInsert;
}
if (rightDeletes.TryGetValue(key, out rightDelete))
{
input |= Ops.RightDelete;
}
// Get propagation rules for the changes
Ops insertRule = m_insertRules[input];
Ops deleteRule = m_deleteRules[input];
if (Ops.Unsupported == insertRule || Ops.Unsupported == deleteRule)
{
// If no propagation rules are defined, it suggests an invalid workload (e.g.
// a required entity or relationship is missing). In general, such exceptions
// should be caught by the RelationshipConstraintValidator, but we defensively
// check for problems here regardless. For instance, a 0..1:1..1 self-assocation
// implied a stronger constraint that cannot be checked by RelationshipConstraintValidator.
// First gather state entries contributing to the problem
List <IEntityStateEntry> stateEntries = new List <IEntityStateEntry>();
Action <Tuple <CompositeKey, PropagatorResult> > addStateEntries = (r) =>
{
if (r != null)
{
stateEntries.AddRange(SourceInterpreter.GetAllStateEntries(r.Item2, this.m_parent.m_updateTranslator,
this.m_parent.m_table));
}
};
addStateEntries(leftInsert);
addStateEntries(leftDelete);
addStateEntries(rightInsert);
addStateEntries(rightDelete);
throw EntityUtil.Update(Strings.Update_InvalidChanges, null, stateEntries);
}
// Where needed, substitute null/unknown placeholders. In some of the join propagation
// rules, we handle the case where a side of the join is 'unknown', or where one side
// of a join is comprised of an record containing only nulls. For instance, we may update
// only one extent appearing in a row of a table (unknown), or; we may insert only
// the left hand side of a left outer join, in which case the right hand side is 'null'.
if (0 != (Ops.LeftUnknown & insertRule))
{
leftInsert = Tuple.Create(key, LeftPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.LeftUnknown & deleteRule))
{
leftDelete = Tuple.Create(key, LeftPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.RightNullModified & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullModified));
}
else if (0 != (Ops.RightNullPreserve & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullPreserve));
}
else if (0 != (Ops.RightUnknown & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.RightNullModified & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullModified));
}
else if (0 != (Ops.RightNullPreserve & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullPreserve));
}
else if (0 != (Ops.RightUnknown & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.Unknown));
}
// Populate elements in join output
if (null != leftInsert && null != rightInsert)
{
result.Inserted.Add(CreateResultTuple(leftInsert, rightInsert, result));
}
if (null != leftDelete && null != rightDelete)
{
result.Deleted.Add(CreateResultTuple(leftDelete, rightDelete, result));
}
}
// Processes all insert and delete requests in the table's <see cref="ChangeNode" />. Inserts
// and deletes with the same key are merged into updates.
internal List<UpdateCommand> CompileCommands(ChangeNode changeNode, UpdateCompiler compiler)
{
Set<CompositeKey> keys = new Set<CompositeKey>(compiler.m_translator.KeyComparer);
// Retrieve all delete results (original values) and insert results (current values) while
// populating a set of all row keys. The set contains a single key per row.
Dictionary<CompositeKey, PropagatorResult> deleteResults = ProcessKeys(compiler, changeNode.Deleted, keys);
Dictionary<CompositeKey, PropagatorResult> insertResults = ProcessKeys(compiler, changeNode.Inserted, keys);
List<UpdateCommand> commands = new List<UpdateCommand>(deleteResults.Count + insertResults.Count);
// Examine each row key to see if the row is being deleted, inserted or updated
foreach (CompositeKey key in keys)
{
PropagatorResult deleteResult;
PropagatorResult insertResult;
bool hasDelete = deleteResults.TryGetValue(key, out deleteResult);
bool hasInsert = insertResults.TryGetValue(key, out insertResult);
Debug.Assert(hasDelete || hasInsert, "(update/TableChangeProcessor) m_keys must not contain a value " +
"if there is no corresponding insert or delete");
try
{
if (!hasDelete)
{
// this is an insert
commands.Add(compiler.BuildInsertCommand(insertResult, this));
}
else if (!hasInsert)
{
// this is a delete
commands.Add(compiler.BuildDeleteCommand(deleteResult, this));
}
else
{
// this is an update because it has both a delete result and an insert result
UpdateCommand updateCommand = compiler.BuildUpdateCommand(deleteResult, insertResult, this);
if (null != updateCommand)
{
// if null is returned, it means it is a no-op update
commands.Add(updateCommand);
}
}
}
catch (Exception e)
{
if (UpdateTranslator.RequiresContext(e))
{
// collect state entries in scope for the current compilation
List<IEntityStateEntry> stateEntries = new List<IEntityStateEntry>();
if (null != deleteResult)
{
stateEntries.AddRange(SourceInterpreter.GetAllStateEntries(
deleteResult, compiler.m_translator, m_table));
}
if (null != insertResult)
{
stateEntries.AddRange(SourceInterpreter.GetAllStateEntries(
insertResult, compiler.m_translator, m_table));
}
throw EntityUtil.Update(System.Data.Entity.Strings.Update_GeneralExecutionException,
e, stateEntries);
}
throw;
}
}
return commands;
}
/// <summary>
/// Produce a tuple containing joined rows.
/// </summary>
/// <param name="left">Left row.</param>
/// <param name="right">Right row.</param>
/// <param name="leftKey">Key used to join left element.</param>
/// <param name="rightKey">Key used to join right element.</param>
/// <param name="result">Result change node; used for type information.</param>
/// <returns>Result of joining the input rows.</returns>
private PropagatorResult CreateResultTuple(Tuple<CompositeKey, PropagatorResult> left, Tuple<CompositeKey, PropagatorResult> right, ChangeNode result)
{
// using ref compare to avoid triggering value based
CompositeKey leftKey = left.Item1;
CompositeKey rightKey = right.Item1;
Dictionary<PropagatorResult, PropagatorResult> map = null;
if (!object.ReferenceEquals(null, leftKey) &&
!object.ReferenceEquals(null, rightKey) &&
!object.ReferenceEquals(leftKey, rightKey))
{
// Merge key values from the left and the right (since they're equal, there's a possibility we'll
// project values only from the left or the right hand side and lose important context.)
CompositeKey mergedKey = leftKey.Merge(m_parent.m_updateTranslator.KeyManager, rightKey);
// create a dictionary so that we can replace key values with merged key values (carrying context
// from both sides)
map = new Dictionary<PropagatorResult, PropagatorResult>();
for (int i = 0; i < leftKey.KeyComponents.Length; i++)
{
map[leftKey.KeyComponents[i]] = mergedKey.KeyComponents[i];
map[rightKey.KeyComponents[i]] = mergedKey.KeyComponents[i];
}
}
PropagatorResult[] joinRecordValues = new PropagatorResult[2];
joinRecordValues[0] = left.Item2;
joinRecordValues[1] = right.Item2;
PropagatorResult join = PropagatorResult.CreateStructuralValue(joinRecordValues, (StructuralType)result.ElementType.EdmType, false);
// replace with merged key values as appropriate
if (null != map)
{
PropagatorResult replacement;
join = join.Replace(original => map.TryGetValue(original, out replacement) ? replacement : original);
}
return join;
}
/// <summary>
/// Propagate all changes associated with a particular join key.
/// </summary>
/// <param name="key">Key.</param>
/// <param name="result">Resulting changes are added to this result.</param>
private void Propagate(CompositeKey key, ChangeNode result, JoinDictionary leftDeletes, JoinDictionary leftInserts,
JoinDictionary rightDeletes, JoinDictionary rightInserts)
{
// Retrieve changes associates with this join key
Tuple<CompositeKey, PropagatorResult> leftInsert = null;
Tuple<CompositeKey, PropagatorResult> leftDelete = null;
Tuple<CompositeKey, PropagatorResult> rightInsert = null;
Tuple<CompositeKey, PropagatorResult> rightDelete = null;
Ops input = Ops.Nothing;
if (leftInserts.TryGetValue(key, out leftInsert)) { input |= Ops.LeftInsert; }
if (leftDeletes.TryGetValue(key, out leftDelete)) { input |= Ops.LeftDelete; }
if (rightInserts.TryGetValue(key, out rightInsert)) { input |= Ops.RightInsert; }
if (rightDeletes.TryGetValue(key, out rightDelete)) { input |= Ops.RightDelete; }
// Get propagation rules for the changes
Ops insertRule = m_insertRules[input];
Ops deleteRule = m_deleteRules[input];
if (Ops.Unsupported == insertRule || Ops.Unsupported == deleteRule)
{
// If no propagation rules are defined, it suggests an invalid workload (e.g.
// a required entity or relationship is missing). In general, such exceptions
// should be caught by the RelationshipConstraintValidator, but we defensively
// check for problems here regardless. For instance, a 0..1:1..1 self-assocation
// implied a stronger constraint that cannot be checked by RelationshipConstraintValidator.
// First gather state entries contributing to the problem
List<IEntityStateEntry> stateEntries = new List<IEntityStateEntry>();
Action<Tuple<CompositeKey, PropagatorResult>> addStateEntries = (r) =>
{
if (r != null)
{
stateEntries.AddRange(SourceInterpreter.GetAllStateEntries(r.Item2, this.m_parent.m_updateTranslator,
this.m_parent.m_table));
}
};
addStateEntries(leftInsert);
addStateEntries(leftDelete);
addStateEntries(rightInsert);
addStateEntries(rightDelete);
throw EntityUtil.Update(Strings.Update_InvalidChanges, null, stateEntries);
}
// Where needed, substitute null/unknown placeholders. In some of the join propagation
// rules, we handle the case where a side of the join is 'unknown', or where one side
// of a join is comprised of an record containing only nulls. For instance, we may update
// only one extent appearing in a row of a table (unknown), or; we may insert only
// the left hand side of a left outer join, in which case the right hand side is 'null'.
if (0 != (Ops.LeftUnknown & insertRule))
{
leftInsert = Tuple.Create(key, LeftPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.LeftUnknown & deleteRule))
{
leftDelete = Tuple.Create(key, LeftPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.RightNullModified & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullModified));
}
else if (0 != (Ops.RightNullPreserve & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullPreserve));
}
else if (0 != (Ops.RightUnknown & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.RightNullModified & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullModified));
}
else if (0 != (Ops.RightNullPreserve & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullPreserve));
}
else if (0 != (Ops.RightUnknown & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.Unknown));
}
// Populate elements in join output
if (null != leftInsert && null != rightInsert)
{
result.Inserted.Add(CreateResultTuple(leftInsert, rightInsert, result));
}
if (null != leftDelete && null != rightDelete)
{
result.Deleted.Add(CreateResultTuple(leftDelete, rightDelete, result));
}
}
/// <summary>
/// Retrieve a change node for an extent. If none exists, creates and registers a new one.
/// </summary>
/// <param name="extent">Extent for which to return a change node.</param>
/// <returns>Change node for requested extent.</returns>
internal ChangeNode GetExtentModifications(EntitySetBase extent)
{
EntityUtil.CheckArgumentNull(extent, "extent");
Debug.Assert(null != m_changes, "(UpdateTranslator/GetChangeNodeForExtent) method called before translator initialized");
ChangeNode changeNode;
if (!m_changes.TryGetValue(extent, out changeNode))
{
changeNode = new ChangeNode(TypeUsage.Create(extent.ElementType));
m_changes.Add(extent, changeNode);
}
return changeNode;
}
// Processes all insert and delete requests in the table's <see cref="ChangeNode" />. Inserts
// and deletes with the same key are merged into updates.
internal List <UpdateCommand> CompileCommands(ChangeNode changeNode, UpdateCompiler compiler)
{
Set <CompositeKey> keys = new Set <CompositeKey>(compiler.m_translator.KeyComparer);
// Retrieve all delete results (original values) and insert results (current values) while
// populating a set of all row keys. The set contains a single key per row.
Dictionary <CompositeKey, PropagatorResult> deleteResults = ProcessKeys(compiler, changeNode.Deleted, keys);
Dictionary <CompositeKey, PropagatorResult> insertResults = ProcessKeys(compiler, changeNode.Inserted, keys);
List <UpdateCommand> commands = new List <UpdateCommand>(deleteResults.Count + insertResults.Count);
// Examine each row key to see if the row is being deleted, inserted or updated
foreach (CompositeKey key in keys)
{
PropagatorResult deleteResult;
PropagatorResult insertResult;
bool hasDelete = deleteResults.TryGetValue(key, out deleteResult);
bool hasInsert = insertResults.TryGetValue(key, out insertResult);
Debug.Assert(hasDelete || hasInsert, "(update/TableChangeProcessor) m_keys must not contain a value " +
"if there is no corresponding insert or delete");
try
{
if (!hasDelete)
{
// this is an insert
commands.Add(compiler.BuildInsertCommand(insertResult, this));
}
else if (!hasInsert)
{
// this is a delete
commands.Add(compiler.BuildDeleteCommand(deleteResult, this));
}
else
{
// this is an update because it has both a delete result and an insert result
UpdateCommand updateCommand = compiler.BuildUpdateCommand(deleteResult, insertResult, this);
if (null != updateCommand)
{
// if null is returned, it means it is a no-op update
commands.Add(updateCommand);
}
}
}
catch (Exception e)
{
if (UpdateTranslator.RequiresContext(e))
{
// collect state entries in scope for the current compilation
List <IEntityStateEntry> stateEntries = new List <IEntityStateEntry>();
if (null != deleteResult)
{
stateEntries.AddRange(SourceInterpreter.GetAllStateEntries(
deleteResult, compiler.m_translator, m_table));
}
if (null != insertResult)
{
stateEntries.AddRange(SourceInterpreter.GetAllStateEntries(
insertResult, compiler.m_translator, m_table));
}
throw EntityUtil.Update(System.Data.Entity.Strings.Update_GeneralExecutionException,
e, stateEntries);
}
throw;
}
}
return(commands);
}
